Contact exploder

Abstract

Actuating circuitry which may be used with a contact exploder, useful on aorpedo, for example, which is sensitive not only to direct hits but also to abrasive damage or sea water exposure caused by grazing contact, but insensitive to changes in its velocity or momentum or unwanted environmental background, such as shock, vibration and electromagnetic field variation. The exploder includes a normally insulated and shielded wire which traverses that part of the surface of the missile which is most likely to make contact with a target. The wire is so connected into associated actuating circuitry that it will cause explosion if: (1) even grazing contact with a target causes removal of even a small amount of the insulation and shielding of the wire, which causes grounding of the circuitry at the wire; or (2) even grazing contact opens or breaks the wire at any point. The circuitry may include a "fail-safe" feature which prevents explosion in the event that the wire has inadvertently opened or shorted before the start of tactical operation.

What is claimed is: 
     
       1. An actuating circuit for a contact exploder comprising: a charging circuit including a charge-discharge capacitor;   an insulated sensing conductor;   means operatively connecting the sensing conductor to the charging circuit for holding the charging circuit in a quiescent condition until the occurrence of at least one of the following: (1) the insulated sensing conductor opens,   (2) a portion of the insulation of the insulated sensing conductor is removed and the sensing conductor is shorted;     the charging circuit, which is adapted for connection to a direct-current power supply, comprising: a differential amplifier, comprising two transistors whose emitters are connected together to a grounded resistor, and whose collectors are connected to the direct-current power supply;     one of the transistors, the first differential transistor, being based biased;   the other transistor, the second differential transistor, having a base which is connected to a grounded resistor and one end of the second conductor, the other end of the sensing conductor being connected to a grounded resistor;   a pulse-forming transistor, whose emitter is connected to the direct-current power supply, whose base is connected to the collector of the first differential transducer, and whose collector is connected to a grounded resistor;   a silicon-controlled rectifier (SCR), whose anode is connected to the direct-current power supply, whose gate is connected to the collector of the pulse-forming transistor, and whose cathode is connected to one end of a squib detonating wire, the other end of the squib being connected through an RC combination to ground, one end of the charge-discharge capacitor being connected to the anode of the SCR, the other end being connected to the junction of the squib and the RC combination;   the following sequence of events occurring if the sensing conductor is either opened or grounded, after a voltage had been applied to the charging circuit; the second differential transistor becomes nonconducting, the first differential transistor begins to conduct, causing collector current to flow in the pulse-forming transistor, which causes a positive pulse to appear at the gate of the silicon-controlled rectifier, forcing it to fire, thereby dumping the charge which had accumulated on the discharge capacitor through the squib detonating wire.   
     
     
       2. The actuating circuit of claim 1 wherein the insulated sensing conductor is mounted in a torpedo. 
     
     
       3. The actuating circuit of claim 2 wherein: the sensing conductor open circuits when the torpedo collides with a target.   
     
     
       4. The actuating circuit of claim 2 wherein the sensing conductor short circuits when the torpedo collides with a target. 
     
     
       5. The actuating circuit of claim 1 wherein the insulated sensing conductor is an insulated wire. 
     
     
       6. The actuating circuit of claim 5 wherein the insulated wire has a helical shape. 
     
     
       7. The actuating circuit of claim 5 wherein the insulated wire has a substantially rectangular waveform shape. 
     
     
       8. The actuating circuit of claim 5 further comprising a squib detonating wire connected to the charging circuit. 
     
     
       9. The actuating circuit of claim 8 further comprising a timing delay circuit for preventing detonation of the squib until the passage of predetermined period of time. 
     
     
       10. The actuating circuit of claim 9 further comprising a fail-safe circuit to prevent detonation of the contact exploder before a predetermined time.